(a) If the moment of force is assigned a negative sign, then will the turning tendency of the force be clockwise or anti-clockwise?

(b) Complete the following nuclear reactions given below

I. $^{238}_{92}\text{P} \overset{\alpha} \longrightarrow \text{Q} \overset{\beta} \longrightarrow \text{R} \overset{\beta} \longrightarrow \text{S}$

II. $^{A}${Z}\text{X} \overset{\alpha} \longrightarrow \text{X}{1} \overset{\gamma} \longrightarrow \text{X}{2} \overset{2\beta} \longrightarrow \text{X}{3}

If a man is travelling in a car in a straight line path and the car suddenly turns right, then the man experiences a severe push towards the left. Explain.

(a) What is meant by an ideal machine?

(b) Write a relationship between the mechanical advantage (MA) and velocity ratio (VR) of an ideal machine.

Define work. State the conditions when the work done by a force acting on a body is zero.